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UniProtKB - P09871 (C1S_HUMAN)

Entry version 249 (25 May 2022)
Sequence version 1 (01 Jul 1989)
Previous versions | rss
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Protein

Complement C1s subcomponent

Gene

C1S

Organism
Homo sapiens (Human)
Status
Reviewed-Annotation score:

Annotation score:5 out of 5

<p>The annotation score provides a heuristic measure of the annotation content of a UniProtKB entry or proteome. This score <strong>cannot</strong> be used as a measure of the accuracy of the annotation as we cannot define the 'correct annotation' for any given protein.<p><a href='/help/annotation_score' target='_top'>More...</a></p>-Experimental evidence at protein leveli <p>This indicates the type of evidence that supports the existence of the protein. Note that the 'protein existence' evidence does not give information on the accuracy or correctness of the sequence(s) displayed.<p><a href='/help/protein_existence' target='_top'>More...</a></p>

<p>This section provides any useful information about the protein, mostly biological knowledge.<p><a href='/help/function_section' target='_top'>More...</a></p>Functioni

C1s B chain is a serine protease that combines with C1q and C1r to form C1, the first component of the classical pathway of the complement system. C1r activates C1s so that it can, in turn, activate C2 and C4.

<p>This subsection of the <a href="http://www.uniprot.org/help/function%5Fsection">Function</a> section describes the catalytic activity of an enzyme, i.e. a chemical reaction that the enzyme catalyzes.<p><a href='/help/catalytic_activity' target='_top'>More...</a></p>Catalytic activityi

  • Cleavage of Arg-|-Ala bond in complement component C4 to form C4a and C4b, and Lys(or Arg)-|-Lys bond in complement component C2 to form C2a and C2b: the 'classical' pathway C3 convertase.1 Publication EC:3.4.21.42

<p>This subsection of the <a href="http://www.uniprot.org/help/function%5Fsection">Function</a> section describes regulatory mechanisms for enzymes, transporters or microbial transcription factors, and reports the components which regulate (by activation or inhibition) the reaction.<p><a href='/help/activity_regulation' target='_top'>More...</a></p>Activity regulationi

Inhibited by SERPING1.1 Publication

<p>This subsection of the 'Function' section describes biophysical and chemical properties, such as maximal absorption, kinetic parameters, pH dependence, redox potentials and temperature dependence.<p><a href='/help/biophysicochemical_properties' target='_top'>More...</a></p>Kineticsi

Less efficient than MASP2 in C4 cleavage.
  1. KM=12.3 µM for complement component C2 (at 37 degrees Celsius)1 Publication
  2. KM=1.9 µM for complement component C4 (at 37 degrees Celsius)1 Publication

Sites

Feature keyPosition(s)DescriptionActionsGraphical viewLength
<p>This subsection of the <a href="http://www.uniprot.org/help/function%5Fsection">Function</a> section indicates at which position the protein binds a given metal ion. The nature of the metal is indicated in the 'Description' field.<p><a href='/help/metal' target='_top'>More...</a></p>Metal bindingi60Calcium1
Metal bindingi68Calcium1
Metal bindingi113Calcium1
Metal bindingi131Calcium1
Metal bindingi132Calcium; via carbonyl oxygen1
Metal bindingi134Calcium1
Metal bindingi149Calcium1
Metal bindingi150Calcium; via carbonyl oxygen1
Metal bindingi153Calcium; via carbonyl oxygen1
<p>This subsection of the <a href="http://www.uniprot.org/help/function%5Fsection">Function</a> section is used for enzymes and indicates the residues directly involved in catalysis.<p><a href='/help/act_site' target='_top'>More...</a></p>Active sitei475Charge relay system1
Active sitei529Charge relay system1
Active sitei632Charge relay system1

<p>The <a href="http://www.geneontology.org/">Gene Ontology (GO)</a> project provides a set of hierarchical controlled vocabulary split into 3 categories:<p><a href='/help/gene_ontology' target='_top'>More...</a></p>GO - Molecular functioni

Complete GO annotation on QuickGO ...

GO - Biological processi

Complete GO annotation on QuickGO ...

<p>UniProtKB Keywords constitute a <a href="http://www.uniprot.org/keywords">controlled vocabulary</a> with a hierarchical structure. Keywords summarise the content of a UniProtKB entry and facilitate the search for proteins of interest.<p><a href='/help/keywords' target='_top'>More...</a></p>Keywordsi

Molecular functionHydrolase, Protease, Serine protease
Biological processComplement pathway, Immunity, Innate immunity
LigandCalcium, Metal-binding

Enzyme and pathway databases

BRENDA Comprehensive Enzyme Information System

More...BRENDAi		3.4.21.42, 2681

Pathway Commons web resource for biological pathway data

More...PathwayCommonsi		P09871

Reactome - a knowledgebase of biological pathways and processes

More...Reactomei		R-HSA-166663, Initial triggering of complement
R-HSA-173623, Classical antibody-mediated complement activation
R-HSA-977606, Regulation of Complement cascade

SABIO-RK: Biochemical Reaction Kinetics Database

More...SABIO-RKi		P09871

SignaLink: a signaling pathway resource with multi-layered regulatory networks

More...SignaLinki		P09871

SIGNOR Signaling Network Open Resource

More...SIGNORi		P09871

Protein family/group databases

MEROPS protease database

More...MEROPSi		S01.193

<p>This section provides information about the protein and gene name(s) and synonym(s) and about the organism that is the source of the protein sequence.<p><a href='/help/names_and_taxonomy_section' target='_top'>More...</a></p>Names & Taxonomyi

<p>This subsection of the <a href="http://www.uniprot.org/help/names%5Fand%5Ftaxonomy%5Fsection">Names and taxonomy</a> section provides an exhaustive list of all names of the protein, from commonly used to obsolete, to allow unambiguous identification of a protein.<p><a href='/help/protein_names' target='_top'>More...</a></p>Protein namesi
Recommended name:
Complement C1s subcomponent (EC:3.4.21.42)
Alternative name(s):
C1 esterase
Complement component 1 subcomponent s
Cleaved into the following 2 chains:
Complement C1s subcomponent heavy chain
Complement C1s subcomponent light chain
<p>This subsection of the <a href="http://www.uniprot.org/help/names%5Fand%5Ftaxonomy%5Fsection">Names and taxonomy</a> section indicates the name(s) of the gene(s) that code for the protein sequence(s) described in the entry. Four distinct tokens exist: 'Name', 'Synonyms', 'Ordered locus names' and 'ORF names'.<p><a href='/help/gene_name' target='_top'>More...</a></p>Gene namesi
Name:C1S
<p>This subsection of the <a href="http://www.uniprot.org/help/names%5Fand%5Ftaxonomy%5Fsection">Names and taxonomy</a> section provides information on the name(s) of the organism that is the source of the protein sequence.<p><a href='/help/organism-name' target='_top'>More...</a></p>OrganismiHomo sapiens (Human)
<p>This subsection of the <a href="http://www.uniprot.org/help/names%5Fand%5Ftaxonomy%5Fsection">Names and taxonomy</a> section shows the unique identifier assigned by the NCBI to the source organism of the protein. This is known as the 'taxonomic identifier' or 'taxid'.<p><a href='/help/taxonomic_identifier' target='_top'>More...</a></p>Taxonomic identifieri9606 [NCBI]
<p>This subsection of the <a href="http://www.uniprot.org/help/names%5Fand%5Ftaxonomy%5Fsection">Names and taxonomy</a> section contains the taxonomic hierarchical classification lineage of the source organism. It lists the nodes as they appear top-down in the taxonomic tree, with the more general grouping listed first.<p><a href='/help/taxonomic_lineage' target='_top'>More...</a></p>Taxonomic lineageiEukaryota › Metazoa › Chordata › Craniata › Vertebrata › Euteleostomi › Mammalia › Eutheria › Euarchontoglires › Primates › Haplorrhini › Catarrhini › Hominidae › Homo
<p>This subsection of the <a href="http://www.uniprot.org/help/names%5Fand%5Ftaxonomy%5Fsection">Names and taxonomy</a> section is present for entries that are part of a <a href="http://www.uniprot.org/proteomes">proteome</a>, i.e. of a set of proteins thought to be expressed by organisms whose genomes have been completely sequenced.<p><a href='/help/proteomes_manual' target='_top'>More...</a></p>Proteomesi
  • UP000005640 <p>A UniProt <a href="http://www.uniprot.org/manual/proteomes%5Fmanual">proteome</a> can consist of several components.<br></br>The component name refers to the genomic component encoding a set of proteins.<p><a href='/help/proteome_component' target='_top'>More...</a></p> Componenti: Chromosome 12

Organism-specific databases

Human Gene Nomenclature Database

More...HGNCi		HGNC:1247, C1S

Online Mendelian Inheritance in Man (OMIM)

More...MIMi		120580, gene

neXtProt; the human protein knowledge platform

More...neXtProti		NX_P09871

Eukaryotic Pathogen, Vector and Host Database Resources

More...VEuPathDBi		HostDB:ENSG00000182326

<p>This section provides information on the location and the topology of the mature protein in the cell.<p><a href='/help/subcellular_location_section' target='_top'>More...</a></p>Subcellular locationi

<p>This section provides information on the disease(s) and phenotype(s) associated with a protein.<p><a href='/help/pathology_and_biotech_section' target='_top'>More...</a></p>Pathology & Biotechi

<p>This subsection of the 'Pathology and Biotech' section provides information on the disease(s) associated with genetic variations in a given protein. The information is extracted from the scientific literature and diseases that are also described in the <a href="http://www.ncbi.nlm.nih.gov/sites/entrez?db=omim">OMIM</a> database are represented with a <a href="http://www.uniprot.org/diseases">controlled vocabulary</a> in the following way:<p><a href='/help/involvement_in_disease' target='_top'>More...</a></p>Involvement in diseasei

Complement component C1s deficiency (C1SD)1 Publication
The disease is caused by variants affecting the gene represented in this entry.
Disease descriptionA rare defect resulting in C1 deficiency and impaired activation of the complement classical pathway. C1 deficiency generally leads to severe immune complex disease with features of systemic lupus erythematosus and glomerulonephritis.
Related information in OMIM
Ehlers-Danlos syndrome, periodontal type, 2 (EDSPD2)1 Publication
The disease is caused by variants affecting the gene represented in this entry.
Disease descriptionA form of Ehlers-Danlos syndrome, a connective tissue disorder characterized by hyperextensible skin, atrophic cutaneous scars due to tissue fragility and joint hyperlaxity. EDSPD2 is characterized by the association of typical features of Ehlers-Danlos syndrome with gingival recession and severe early-onset periodontal disease, leading to premature loss of permanent teeth. EDSPD2 transmission pattern is consistent with autosomal dominant inheritance.
Related information in OMIM
Feature keyPosition(s)DescriptionActionsGraphical viewLength
<p>This subsection of the 'Sequence' section describes natural variant(s) of the protein sequence.<p><a href='/help/variant' target='_top'>More...</a></p>Natural variantiVAR_077120294C → R in EDSPD2. 1 PublicationCorresponds to variant dbSNP:rs886040975EnsemblClinVar.1
Natural variantiVAR_077121316Missing in EDSPD2; unknown pathological significance. 1 Publication1

Keywords - Diseasei

Disease variant, Ehlers-Danlos syndrome

Organism-specific databases

DisGeNET

More...DisGeNETi		716

GeneReviews a resource of expert-authored, peer-reviewed disease descriptions.

More...GeneReviewsi		C1S

MalaCards human disease database

More...MalaCardsi		C1S
MIMi613783, phenotype
617174, phenotype

Open Targets

More...OpenTargetsi		ENSG00000182326

Orphanet; a database dedicated to information on rare diseases and orphan drugs

More...Orphaneti		169147, Immunodeficiency due to a classical component pathway complement deficiency
75392, Periodontal Ehlers-Danlos syndrome

The Pharmacogenetics and Pharmacogenomics Knowledge Base

More...PharmGKBi		PA25636

Miscellaneous databases

Pharos NIH Druggable Genome Knowledgebase

More...Pharosi		P09871, Tchem

Chemistry databases

ChEMBL database of bioactive drug-like small molecules

More...ChEMBLi		CHEMBL3913

Drug and drug target database

More...DrugBanki		DB02371, 2-(2-Hydroxy-1,1-Dihydroxymethyl-Ethylamino)-Ethanesulfonic Acid
DB09228, Conestat alfa
DB09130, Copper
DB12831, Gabexate
DB06404, Human C1-esterase inhibitor
DB01593, Zinc
DB14487, Zinc acetate
DB14533, Zinc chloride
DB14548, Zinc sulfate, unspecified form

DrugCentral

More...DrugCentrali		P09871

IUPHAR/BPS Guide to PHARMACOLOGY

More...GuidetoPHARMACOLOGYi		2335

Genetic variation databases

BioMuta curated single-nucleotide variation and disease association database

More...BioMutai		C1S

Domain mapping of disease mutations (DMDM)

More...DMDMi		115205

<p>This section describes post-translational modifications (PTMs) and/or processing events.<p><a href='/help/ptm_processing_section' target='_top'>More...</a></p>PTM / Processingi

Molecule processing

Feature keyPosition(s)DescriptionActionsGraphical viewLength
<p>This subsection of the 'PTM / Processing' section denotes the presence of an N-terminal signal peptide.<p><a href='/help/signal' target='_top'>More...</a></p>Signal peptidei1 – 151 PublicationAdd BLAST15
<p>This subsection of the 'PTM / Processing' section describes the extent of a polypeptide chain in the mature protein following processing or proteolytic cleavage.<p><a href='/help/chain' target='_top'>More...</a></p>ChainiPRO_000002758616 – 688Complement C1s subcomponentAdd BLAST673
ChainiPRO_000002758716 – 437Complement C1s subcomponent heavy chainAdd BLAST422
ChainiPRO_0000027588438 – 688Complement C1s subcomponent light chainAdd BLAST251

Amino acid modifications

Feature keyPosition(s)DescriptionActionsGraphical viewLength
<p>This subsection of the PTM / Processing":/help/ptm_processing_section section describes the positions of cysteine residues participating in disulfide bonds.<p><a href='/help/disulfid' target='_top'>More...</a></p>Disulfide bondi65 ↔ 831 Publication
Disulfide bondi135 ↔ 1471 Publication
Disulfide bondi143 ↔ 1561 Publication
<p>This subsection of the 'PTM / Processing' section specifies the position and type of each modified residue excluding <a href="http://www.uniprot.org/manual/lipid">lipids</a>, <a href="http://www.uniprot.org/manual/carbohyd">glycans</a> and <a href="http://www.uniprot.org/manual/crosslnk">protein cross-links</a>.<p><a href='/help/mod_res' target='_top'>More...</a></p>Modified residuei149(3R)-3-hydroxyasparagine1 Publication1
Disulfide bondi158 ↔ 1711 Publication
<p>This subsection of the <a href="http://www.uniprot.org/help/ptm%5Fprocessing%5Fsection">PTM / Processing</a> section specifies the position and type of each covalently attached glycan group (mono-, di-, or polysaccharide).<p><a href='/help/carbohyd' target='_top'>More...</a></p>Glycosylationi174N-linked (GlcNAc...) asparagine2 Publications1
Disulfide bondi175 ↔ 2021 Publication
Disulfide bondi234 ↔ 2511 Publication
Disulfide bondi294 ↔ 3411 Publication
Disulfide bondi321 ↔ 3541 Publication
Disulfide bondi359 ↔ 4031 Publication
Disulfide bondi386 ↔ 4211 Publication
Glycosylationi406N-linked (GlcNAc...) asparagine3 Publications1
Disulfide bondi425 ↔ 549Interchain (between heavy and light chains)PROSITE-ProRule annotation1 Publication
Disulfide bondi595 ↔ 6181 Publication
Disulfide bondi628 ↔ 6591 Publication

<p>This subsection of the <a href="http://www.uniprot.org/help/ptm%5Fprocessing%5Fsection">PTM/processing</a> section describes post-translational modifications (PTMs). This subsection <strong>complements</strong> the information provided at the sequence level or describes modifications for which <strong>position-specific data is not yet available</strong>.<p><a href='/help/post-translational_modification' target='_top'>More...</a></p>Post-translational modificationi

The iron and 2-oxoglutarate dependent 3-hydroxylation of aspartate and asparagine is (R) stereospecific within EGF domains.1 Publication

Keywords - PTMi

Disulfide bond, Glycoprotein, Hydroxylation

Proteomic databases

The CPTAC Assay portal

More...CPTACi		non-CPTAC-1103

Encyclopedia of Proteome Dynamics

More...EPDi		P09871

jPOST - Japan Proteome Standard Repository/Database

More...jPOSTi		P09871

MassIVE - Mass Spectrometry Interactive Virtual Environment

More...MassIVEi		P09871

MaxQB - The MaxQuant DataBase

More...MaxQBi		P09871

PaxDb, a database of protein abundance averages across all three domains of life

More...PaxDbi		P09871

PeptideAtlas

More...PeptideAtlasi		P09871

PRoteomics IDEntifications database

More...PRIDEi		P09871

ProteomicsDB: a multi-organism proteome resource

More...ProteomicsDBi		52270

2D gel databases

Two-dimensional polyacrylamide gel electrophoresis database from the Geneva University Hospital

More...SWISS-2DPAGEi		P09871

PTM databases

GlyConnect protein glycosylation platform

More...GlyConnecti		1144, 4 N-Linked glycans (2 sites)

GlyGen: Computational and Informatics Resources for Glycoscience

More...GlyGeni		P09871, 2 sites, 7 N-linked glycans (2 sites)

iPTMnet integrated resource for PTMs in systems biology context

More...iPTMneti		P09871

Comprehensive resource for the study of protein post-translational modifications (PTMs) in human, mouse and rat.

More...PhosphoSitePlusi		P09871

<p>This section provides information on the expression of a gene at the mRNA or protein level in cells or in tissues of multicellular organisms.<p><a href='/help/expression_section' target='_top'>More...</a></p>Expressioni

Gene expression databases

Bgee dataBase for Gene Expression Evolution

More...Bgeei		ENSG00000182326, Expressed in right lobe of liver and 240 other tissues

ExpressionAtlas, Differential and Baseline Expression

More...ExpressionAtlasi		P09871, baseline and differential

Genevisible search portal to normalized and curated expression data from Genevestigator

More...Genevisiblei		P09871, HS

Organism-specific databases

Human Protein Atlas

More...HPAi		ENSG00000182326, Tissue enriched (liver)

<p>This section provides information on the quaternary structure of a protein and on interaction(s) with other proteins or protein complexes.<p><a href='/help/interaction_section' target='_top'>More...</a></p>Interactioni

<p>This subsection of the <a href="http://www.uniprot.org/help/interaction%5Fsection">'Interaction'</a> section provides information about the protein quaternary structure and interaction(s) with other proteins or protein complexes (with the exception of physiological receptor-ligand interactions which are annotated in the <a href="http://www.uniprot.org/help/function%5Fsection">'Function'</a> section).<p><a href='/help/subunit_structure' target='_top'>More...</a></p>Subunit structurei

C1 is a calcium-dependent trimolecular complex of C1q, C1r and C1s in the molar ration of 1:2:2. Activated C1s is an disulfide-linked heterodimer of a heavy chain and a light chain.

1 Publication

<p>This subsection of the '<a href="http://www.uniprot.org/help/interaction%5Fsection">Interaction</a>' section provides information about binary protein-protein interactions. The data presented in this section are a quality-filtered subset of binary interactions automatically derived from the <a href="https://www.ebi.ac.uk/intact/">IntAct database</a>. It is updated at every <a href="http://www.uniprot.org/help/synchronization">UniProt release</a>.<p><a href='/help/binary_interactions' target='_top'>More...</a></p>Binary interactionsi

Hide details

GO - Molecular functioni

Complete GO annotation on QuickGO ...

Protein-protein interaction databases

The Biological General Repository for Interaction Datasets (BioGRID)

More...BioGRIDi		107177, 13 interactors

ComplexPortal: manually curated resource of macromolecular complexes

More...ComplexPortali		CPX-1920, Complement C1 complex

Protein interaction database and analysis system

More...IntActi		P09871, 17 interactors

Molecular INTeraction database

More...MINTi		P09871

STRING: functional protein association networks

More...STRINGi		9606.ENSP00000385035

Chemistry databases

BindingDB database of measured binding affinities

More...BindingDBi		P09871

Miscellaneous databases

RNAct, Protein-RNA interaction predictions for model organisms.

More...RNActi		P09871, protein

<p>This section provides information on the tertiary and secondary structure of a protein.<p><a href='/help/structure_section' target='_top'>More...</a></p>Structurei

Secondary structure

1688
Legend: HelixTurnBeta strandPDB Structure known for this area
Show more details

3D structure databases

AlphaFold Protein Structure Database

More...AlphaFoldDBi		P09871

Small Angle Scattering Biological Data Bank

More...SASBDBi		P09871

SWISS-MODEL Repository - a database of annotated 3D protein structure models

More...SMRi		P09871

Database of comparative protein structure models

More...ModBasei		Search...

Protein Data Bank in Europe - Knowledge Base

More...PDBe-KBi		Search...

Miscellaneous databases

Relative evolutionary importance of amino acids within a protein sequence

More...EvolutionaryTracei		P09871

<p>This section provides information on sequence similarities with other proteins and the domain(s) present in a protein.<p><a href='/help/family_and_domains_section' target='_top'>More...</a></p>Family & Domainsi

Domains and Repeats

Feature keyPosition(s)DescriptionActionsGraphical viewLength
<p>This subsection of the <a href="http://www.uniprot.org/help/family%5Fand%5Fdomains%5Fsection">Family and Domains</a> section describes the position and type of a domain, which is defined as a specific combination of secondary structures organized into a characteristic three-dimensional structure or fold.<p><a href='/help/domain' target='_top'>More...</a></p>Domaini16 – 130CUB 1PROSITE-ProRule annotationAdd BLAST115
Domaini131 – 172EGF-like; calcium-bindingAdd BLAST42
Domaini175 – 290CUB 2PROSITE-ProRule annotationAdd BLAST116
Domaini292 – 356Sushi 1PROSITE-ProRule annotationAdd BLAST65
Domaini357 – 423Sushi 2PROSITE-ProRule annotationAdd BLAST67
Domaini438 – 680Peptidase S1PROSITE-ProRule annotationAdd BLAST243

<p>This subsection of the 'Family and domains' section provides information about the sequence similarity with other proteins.<p><a href='/help/sequence_similarities' target='_top'>More...</a></p>Sequence similaritiesi

Belongs to the peptidase S1 family.PROSITE-ProRule annotation

Keywords - Domaini

EGF-like domain, Repeat, Signal, Sushi

Phylogenomic databases

evolutionary genealogy of genes: Non-supervised Orthologous Groups

More...eggNOGi		KOG3627, Eukaryota

Ensembl GeneTree

More...GeneTreei		ENSGT00940000157473

The HOGENOM Database of Homologous Genes from Fully Sequenced Organisms

More...HOGENOMi		CLU_006842_14_1_1

InParanoid: Eukaryotic Ortholog Groups

More...InParanoidi		P09871

Identification of Orthologs from Complete Genome Data

More...OMAi		DFADAPC

Database of Orthologous Groups

More...OrthoDBi		6580at2759

Database for complete collections of gene phylogenies

More...PhylomeDBi		P09871

TreeFam database of animal gene trees

More...TreeFami		TF330373

Family and domain databases

Conserved Domains Database

More...CDDi		cd00033, CCP, 2 hits
cd00041, CUB, 2 hits
cd00190, Tryp_SPc, 1 hit

Gene3D Structural and Functional Annotation of Protein Families

More...Gene3Di		2.40.10.10, 2 hits
2.60.120.290, 2 hits

Integrated resource of protein families, domains and functional sites

More...InterProi		View protein in InterPro
IPR035708, Complement_C1s_subcomponent
IPR000859, CUB_dom
IPR001881, EGF-like_Ca-bd_dom
IPR000152, EGF-type_Asp/Asn_hydroxyl_site
IPR018097, EGF_Ca-bd_CS
IPR009003, Peptidase_S1_PA
IPR043504, Peptidase_S1_PA_chymotrypsin
IPR001314, Peptidase_S1A
IPR035914, Sperma_CUB_dom_sf
IPR035976, Sushi/SCR/CCP_sf
IPR000436, Sushi_SCR_CCP_dom
IPR001254, Trypsin_dom
IPR033116, TRYPSIN_SER

The PANTHER Classification System

More...PANTHERi		PTHR24255:SF18, PTHR24255:SF18, 1 hit

Pfam protein domain database

More...Pfami		View protein in Pfam
PF00431, CUB, 2 hits
PF00084, Sushi, 2 hits
PF00089, Trypsin, 1 hit

Protein Motif fingerprint database; a protein domain database

More...PRINTSi		PR00722, CHYMOTRYPSIN

Simple Modular Architecture Research Tool; a protein domain database

More...SMARTi		View protein in SMART
SM00032, CCP, 2 hits
SM00042, CUB, 2 hits
SM00179, EGF_CA, 1 hit
SM00020, Tryp_SPc, 1 hit

Superfamily database of structural and functional annotation

More...SUPFAMi		SSF49854, SSF49854, 2 hits
SSF50494, SSF50494, 1 hit
SSF57535, SSF57535, 2 hits

PROSITE; a protein domain and family database

More...PROSITEi		View protein in PROSITE
PS00010, ASX_HYDROXYL, 1 hit
PS01180, CUB, 2 hits
PS01187, EGF_CA, 1 hit
PS50923, SUSHI, 2 hits
PS50240, TRYPSIN_DOM, 1 hit
PS00135, TRYPSIN_SER, 1 hit

<p>This section displays by default the canonical protein sequence and upon request all isoforms described in the entry. It also includes information pertinent to the sequence(s), including <a href="http://www.uniprot.org/help/sequence%5Flength">length</a> and <a href="http://www.uniprot.org/help/sequences">molecular weight</a>. The information is filed in different subsections. The current subsections and their content are listed below:<p><a href='/help/sequences_section' target='_top'>More...</a></p>Sequence (1+)i

<p>This subsection of the <a href="http://www.uniprot.org/help/sequences%5Fsection">Sequence</a> section indicates if the <a href="http://www.uniprot.org/help/canonical%5Fand%5Fisoforms">canonical sequence</a> displayed by default in the entry is complete or not.<p><a href='/help/sequence_status' target='_top'>More...</a></p>Sequence statusi: Complete.

<p>This subsection of the <a href="http://www.uniprot.org/help/sequences%5Fsection">Sequence</a> section indicates if the <a href="http://www.uniprot.org/help/canonical%5Fand%5Fisoforms">canonical sequence</a> displayed by default in the entry is in its mature form or if it represents the precursor.<p><a href='/help/sequence_processing' target='_top'>More...</a></p>Sequence processingi: The displayed sequence is further processed into a mature form.

This entry has 1 described isoform and 6 potential isoforms that are computationally mapped.Show allAlign All

P09871-1 [UniParc]FASTAAdd to basket
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MWCIVLFSLL AWVYAEPTMY GEILSPNYPQ AYPSEVEKSW DIEVPEGYGI 
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HLYFTHLDIE LSENCAYDSV QIISGDTEEG RLCGQRSSNN PHSPIVEEFQ 
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VPYNKLQVIF KSDFSNEERF TGFAAYYVAT DINECTDFVD VPCSHFCNNF 
       160        170        180        190        200
IGGYFCSCPP EYFLHDDMKN CGVNCSGDVF TALIGEIASP NYPKPYPENS 
       210        220        230        240        250
RCEYQIRLEK GFQVVVTLRR EDFDVEAADS AGNCLDSLVF VAGDRQFGPY 
       260        270        280        290        300
CGHGFPGPLN IETKSNALDI IFQTDLTGQK KGWKLRYHGD PMPCPKEDTP 
       310        320        330        340        350
NSVWEPAKAK YVFRDVVQIT CLDGFEVVEG RVGATSFYST CQSNGKWSNS 
       360        370        380        390        400
KLKCQPVDCG IPESIENGKV EDPESTLFGS VIRYTCEEPY YYMENGGGGE 
       410        420        430        440        450
YHCAGNGSWV NEVLGPELPK CVPVCGVPRE PFEEKQRIIG GSDADIKNFP 
       460        470        480        490        500
WQVFFDNPWA GGALINEYWV LTAAHVVEGN REPTMYVGST SVQTSRLAKS 
       510        520        530        540        550
KMLTPEHVFI HPGWKLLEVP EGRTNFDNDI ALVRLKDPVK MGPTVSPICL 
       560        570        580        590        600
PGTSSDYNLM DGDLGLISGW GRTEKRDRAV RLKAARLPVA PLRKCKEVKV 
       610        620        630        640        650
EKPTADAEAY VFTPNMICAG GEKGMDSCKG DSGGAFAVQD PNDKTKFYAA 
       660        670        680 
GLVSWGPQCG TYGLYTRVKN YVDWIMKTMQ ENSTPRED
Length:688
Mass (Da):76,684
Last modified:July 1, 1989 - v1
<p>The checksum is a form of redundancy check that is calculated from the sequence. It is useful for tracking sequence updates.</p> <p>It should be noted that while, in theory, two different sequences could have the same checksum value, the likelihood that this would happen is extremely low.</p> <p>However UniProtKB may contain entries with identical sequences in case of multiple genes (paralogs).</p> <p>The checksum is computed as the sequence 64-bit Cyclic Redundancy Check value (CRC64) using the generator polynomial: x<sup>64</sup> + x<sup>4</sup> + x<sup>3</sup> + x + 1. The algorithm is described in the ISO 3309 standard. </p> <p class="publication">Press W.H., Flannery B.P., Teukolsky S.A. and Vetterling W.T.<br /> <strong>Cyclic redundancy and other checksums</strong><br /> <a href="http://www.nrbook.com/b/bookcpdf.php">Numerical recipes in C 2nd ed., pp896-902, Cambridge University Press (1993)</a>)</p> Checksum:i85522647A4C47205
GO

<p>In eukaryotic reference proteomes, unreviewed entries that are likely to belong to the same gene are computationally mapped, based on gene identifiers from Ensembl, EnsemblGenomes and model organism databases.<p><a href='/help/gene_centric_isoform_mapping' target='_top'>More...</a></p>Computationally mapped potential isoform sequencesi

There are 6 potential isoforms mapped to this entry.BLASTAlignShow allAdd to basket
EntryEntry nameProtein names
Gene namesLengthAnnotation
B5MCV4B5MCV4_HUMAN
Complement C1s subcomponent
C1S
168Annotation score:

Annotation score:1 out of 5

<p>The annotation score provides a heuristic measure of the annotation content of a UniProtKB entry or proteome. This score <strong>cannot</strong> be used as a measure of the accuracy of the annotation as we cannot define the 'correct annotation' for any given protein.<p><a href='/help/annotation_score' target='_top'>More...</a></p>
C9JY52C9JY52_HUMAN
Complement C1s subcomponent
C1S
100Annotation score:

Annotation score:1 out of 5

<p>The annotation score provides a heuristic measure of the annotation content of a UniProtKB entry or proteome. This score <strong>cannot</strong> be used as a measure of the accuracy of the annotation as we cannot define the 'correct annotation' for any given protein.<p><a href='/help/annotation_score' target='_top'>More...</a></p>
F8WCZ6F8WCZ6_HUMAN
Complement C1s subcomponent
C1S
521Annotation score:

Annotation score:1 out of 5

<p>The annotation score provides a heuristic measure of the annotation content of a UniProtKB entry or proteome. This score <strong>cannot</strong> be used as a measure of the accuracy of the annotation as we cannot define the 'correct annotation' for any given protein.<p><a href='/help/annotation_score' target='_top'>More...</a></p>
H0Y5D1H0Y5D1_HUMAN
Complement C1s subcomponent
C1S
355Annotation score:

Annotation score:1 out of 5

<p>The annotation score provides a heuristic measure of the annotation content of a UniProtKB entry or proteome. This score <strong>cannot</strong> be used as a measure of the accuracy of the annotation as we cannot define the 'correct annotation' for any given protein.<p><a href='/help/annotation_score' target='_top'>More...</a></p>
C9IZP8C9IZP8_HUMAN
Complement C1s subcomponent
C1S
103Annotation score:

Annotation score:1 out of 5

<p>The annotation score provides a heuristic measure of the annotation content of a UniProtKB entry or proteome. This score <strong>cannot</strong> be used as a measure of the accuracy of the annotation as we cannot define the 'correct annotation' for any given protein.<p><a href='/help/annotation_score' target='_top'>More...</a></p>
F5H7T4F5H7T4_HUMAN
Complement C1s subcomponent
C1S
157Annotation score:

Annotation score:1 out of 5

<p>The annotation score provides a heuristic measure of the annotation content of a UniProtKB entry or proteome. This score <strong>cannot</strong> be used as a measure of the accuracy of the annotation as we cannot define the 'correct annotation' for any given protein.<p><a href='/help/annotation_score' target='_top'>More...</a></p>

Experimental Info

Feature keyPosition(s)DescriptionActionsGraphical viewLength
<p>This subsection of the 'Sequence' section reports difference(s) between the canonical sequence (displayed by default in the entry) and the different sequence submissions merged in the entry. These various submissions may originate from different sequencing projects, different types of experiments, or different biological samples. Sequence conflicts are usually of unknown origin.<p><a href='/help/conflict' target='_top'>More...</a></p>Sequence conflicti294C → K AA sequence (PubMed:3007145).Curated1
Sequence conflicti513G → GG (PubMed:2553984).Curated1
Sequence conflicti573T → A AA sequence (PubMed:6362661).Curated1
Sequence conflicti645 – 646TK → GR AA sequence (PubMed:6362661).Curated2

Natural variant

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Natural variantiVAR_033643119R → H. Corresponds to variant dbSNP:rs12146727Ensembl.1
Natural variantiVAR_077120294C → R in EDSPD2. 1 PublicationCorresponds to variant dbSNP:rs886040975EnsemblClinVar.1
Natural variantiVAR_077121316Missing in EDSPD2; unknown pathological significance. 1 Publication1
Natural variantiVAR_033644327V → L. Corresponds to variant dbSNP:rs2239170EnsemblClinVar.1
Natural variantiVAR_014565383R → H. Corresponds to variant dbSNP:rs20573EnsemblClinVar.1

Sequence databases

Select the link destinations:

EMBL nucleotide sequence database

More...EMBLi

GenBank nucleotide sequence database

More...GenBanki

DNA Data Bank of Japan; a nucleotide sequence database

More...DDBJi
Links Updated
X06596 mRNA Translation: CAA29817.1
M18767 mRNA Translation: AAA51853.1
J04080 mRNA Translation: AAA51852.1
CH471116 Genomic DNA Translation: EAW88689.1
CH471116 Genomic DNA Translation: EAW88690.1
BC056903 mRNA Translation: AAH56903.1
AB009076 Genomic DNA Translation: BAA86864.1

The Consensus CDS (CCDS) project

More...CCDSi		CCDS31735.1

Protein sequence database of the Protein Information Resource

More...PIRi		A40496, C1HUS

NCBI Reference Sequences

More...RefSeqi		NP_001333779.1, NM_001346850.1
NP_001725.1, NM_001734.4
NP_958850.1, NM_201442.3
XP_005253817.1, XM_005253760.1

Genome annotation databases

Ensembl eukaryotic genome annotation project

More...Ensembli		ENST00000328916.7; ENSP00000328173.3; ENSG00000182326.16
ENST00000360817.10; ENSP00000354057.5; ENSG00000182326.16
ENST00000406697.5; ENSP00000385035.1; ENSG00000182326.16

Database of genes from NCBI RefSeq genomes

More...GeneIDi		716

KEGG: Kyoto Encyclopedia of Genes and Genomes

More...KEGGi		hsa:716

Matched Annotation from NCBI and EMBL-EBI (MANE) - Phase one

More...MANE-Selecti		ENST00000360817.10; ENSP00000354057.5; NM_001734.5; NP_001725.1

UCSC genome browser

More...UCSCi		uc001qsj.4, human

<p>This section provides links to proteins that are similar to the protein sequence(s) described in this entry at different levels of sequence identity thresholds (100%, 90% and 50%) based on their membership in UniProt Reference Clusters (<a href="http://www.uniprot.org/help/uniref">UniRef</a>).<p><a href='/help/similar_proteins_section' target='_top'>More...</a></p>Similar proteinsi

<p>This section is used to point to information related to entries and found in data collections other than UniProtKB.<p><a href='/help/cross_references_section' target='_top'>More...</a></p>Cross-referencesi

<p>This subsection of the <a href="http://www.uniprot.org/manual/cross%5Freferences%5Fsection">Cross-references</a> section provides links to various web resources that are relevant for a specific protein.<p><a href='/help/web_resource' target='_top'>More...</a></p>Web resourcesi

C1Sbase

C1S mutation db

Sequence databases

Select the link destinations:
EMBLi
GenBanki
DDBJi
Links Updated
X06596 mRNA Translation: CAA29817.1
M18767 mRNA Translation: AAA51853.1
J04080 mRNA Translation: AAA51852.1
CH471116 Genomic DNA Translation: EAW88689.1
CH471116 Genomic DNA Translation: EAW88690.1
BC056903 mRNA Translation: AAH56903.1
AB009076 Genomic DNA Translation: BAA86864.1
CCDSiCCDS31735.1
PIRiA40496, C1HUS
RefSeqiNP_001333779.1, NM_001346850.1
NP_001725.1, NM_001734.4
NP_958850.1, NM_201442.3
XP_005253817.1, XM_005253760.1

3D structure databases

Select the link destinations:

Protein Data Bank Europe

More...PDBei

Protein Data Bank RCSB

More...RCSB PDBi

Protein Data Bank Japan

More...PDBji
Links Updated
PDB entryMethodResolution (Å)ChainPositionsPDBsum
1ELVX-ray1.70A356-688[»]
1NZIX-ray1.50A/B16-174[»]
4J1YX-ray2.66A/B292-688[»]
4LMFX-ray2.92A/B/C/D17-292[»]
4LORX-ray2.50A17-292[»]
4LOSX-ray2.00A172-358[»]
4LOTX-ray2.92A175-423[»]
6F1CX-ray4.20B/D16-292[»]
6F1HX-ray4.50B/D17-292[»]
AlphaFoldDBiP09871
SASBDBiP09871
SMRiP09871
ModBaseiSearch...
PDBe-KBiSearch...

Protein-protein interaction databases

BioGRIDi107177, 13 interactors
ComplexPortaliCPX-1920, Complement C1 complex
IntActiP09871, 17 interactors
MINTiP09871
STRINGi9606.ENSP00000385035

Chemistry databases

BindingDBiP09871
ChEMBLiCHEMBL3913
DrugBankiDB02371, 2-(2-Hydroxy-1,1-Dihydroxymethyl-Ethylamino)-Ethanesulfonic Acid
DB09228, Conestat alfa
DB09130, Copper
DB12831, Gabexate
DB06404, Human C1-esterase inhibitor
DB01593, Zinc
DB14487, Zinc acetate
DB14533, Zinc chloride
DB14548, Zinc sulfate, unspecified form
DrugCentraliP09871
GuidetoPHARMACOLOGYi2335

Protein family/group databases

MEROPSiS01.193

PTM databases

GlyConnecti1144, 4 N-Linked glycans (2 sites)
GlyGeniP09871, 2 sites, 7 N-linked glycans (2 sites)
iPTMnetiP09871
PhosphoSitePlusiP09871

Genetic variation databases

BioMutaiC1S
DMDMi115205

2D gel databases

SWISS-2DPAGEiP09871

Proteomic databases

CPTACinon-CPTAC-1103
EPDiP09871
jPOSTiP09871
MassIVEiP09871
MaxQBiP09871
PaxDbiP09871
PeptideAtlasiP09871
PRIDEiP09871
ProteomicsDBi52270

Protocols and materials databases

ABCD curated depository of sequenced antibodies

More...ABCDi		P09871, 28 sequenced antibodies

Antibodypedia a portal for validated antibodies

More...Antibodypediai		3384, 625 antibodies from 35 providers

The DNASU plasmid repository

More...DNASUi		716

Genome annotation databases

EnsembliENST00000328916.7; ENSP00000328173.3; ENSG00000182326.16
ENST00000360817.10; ENSP00000354057.5; ENSG00000182326.16
ENST00000406697.5; ENSP00000385035.1; ENSG00000182326.16
GeneIDi716
KEGGihsa:716
MANE-SelectiENST00000360817.10; ENSP00000354057.5; NM_001734.5; NP_001725.1
UCSCiuc001qsj.4, human

Organism-specific databases

Comparative Toxicogenomics Database

More...CTDi		716
DisGeNETi716

GeneCards: human genes, protein and diseases

More...GeneCardsi		C1S
GeneReviewsiC1S
HGNCiHGNC:1247, C1S
HPAiENSG00000182326, Tissue enriched (liver)
MalaCardsiC1S
MIMi120580, gene
613783, phenotype
617174, phenotype
neXtProtiNX_P09871
OpenTargetsiENSG00000182326
Orphaneti169147, Immunodeficiency due to a classical component pathway complement deficiency
75392, Periodontal Ehlers-Danlos syndrome
PharmGKBiPA25636
VEuPathDBiHostDB:ENSG00000182326

GenAtlas: human gene database

More...GenAtlasi		Search...

Phylogenomic databases

eggNOGiKOG3627, Eukaryota
GeneTreeiENSGT00940000157473
HOGENOMiCLU_006842_14_1_1
InParanoidiP09871
OMAiDFADAPC
OrthoDBi6580at2759
PhylomeDBiP09871
TreeFamiTF330373

Enzyme and pathway databases

BRENDAi3.4.21.42, 2681
PathwayCommonsiP09871
ReactomeiR-HSA-166663, Initial triggering of complement
R-HSA-173623, Classical antibody-mediated complement activation
R-HSA-977606, Regulation of Complement cascade
SABIO-RKiP09871
SignaLinkiP09871
SIGNORiP09871

Miscellaneous databases

BioGRID ORCS database of CRISPR phenotype screens

More...BioGRID-ORCSi		716, 13 hits in 1075 CRISPR screens

ChiTaRS: a database of human, mouse and fruit fly chimeric transcripts and RNA-sequencing data

More...ChiTaRSi		C1S, human
EvolutionaryTraceiP09871

The Gene Wiki collection of pages on human genes and proteins

More...GeneWikii		C1S

Database of phenotypes from RNA interference screens in Drosophila and Homo sapiens

More...GenomeRNAii		716
PharosiP09871, Tchem

Protein Ontology

More...PROi		PR:P09871
RNActiP09871, protein

The Stanford Online Universal Resource for Clones and ESTs

More...SOURCEi		Search...

Gene expression databases

BgeeiENSG00000182326, Expressed in right lobe of liver and 240 other tissues
ExpressionAtlasiP09871, baseline and differential
GenevisibleiP09871, HS

Family and domain databases

CDDicd00033, CCP, 2 hits
cd00041, CUB, 2 hits
cd00190, Tryp_SPc, 1 hit
Gene3Di2.40.10.10, 2 hits
2.60.120.290, 2 hits
InterProiView protein in InterPro
IPR035708, Complement_C1s_subcomponent
IPR000859, CUB_dom
IPR001881, EGF-like_Ca-bd_dom
IPR000152, EGF-type_Asp/Asn_hydroxyl_site
IPR018097, EGF_Ca-bd_CS
IPR009003, Peptidase_S1_PA
IPR043504, Peptidase_S1_PA_chymotrypsin
IPR001314, Peptidase_S1A
IPR035914, Sperma_CUB_dom_sf
IPR035976, Sushi/SCR/CCP_sf
IPR000436, Sushi_SCR_CCP_dom
IPR001254, Trypsin_dom
IPR033116, TRYPSIN_SER
PANTHERiPTHR24255:SF18, PTHR24255:SF18, 1 hit
PfamiView protein in Pfam
PF00431, CUB, 2 hits
PF00084, Sushi, 2 hits
PF00089, Trypsin, 1 hit
PRINTSiPR00722, CHYMOTRYPSIN
SMARTiView protein in SMART
SM00032, CCP, 2 hits
SM00042, CUB, 2 hits
SM00179, EGF_CA, 1 hit
SM00020, Tryp_SPc, 1 hit
SUPFAMiSSF49854, SSF49854, 2 hits
SSF50494, SSF50494, 1 hit
SSF57535, SSF57535, 2 hits
PROSITEiView protein in PROSITE
PS00010, ASX_HYDROXYL, 1 hit
PS01180, CUB, 2 hits
PS01187, EGF_CA, 1 hit
PS50923, SUSHI, 2 hits
PS50240, TRYPSIN_DOM, 1 hit
PS00135, TRYPSIN_SER, 1 hit

MobiDB: a database of protein disorder and mobility annotations

More...MobiDBi		Search...

<p>This section provides general information on the entry.<p><a href='/help/entry_information_section' target='_top'>More...</a></p>Entry informationi

<p>This subsection of the 'Entry information' section provides a mnemonic identifier for a UniProtKB entry, but it is not a stable identifier. Each reviewed entry is assigned a unique entry name upon integration into UniProtKB/Swiss-Prot.<p><a href='/help/entry_name' target='_top'>More...</a></p>Entry nameiC1S_HUMAN
<p>This subsection of the 'Entry information' section provides one or more accession number(s). These are stable identifiers and should be used to cite UniProtKB entries. Upon integration into UniProtKB, each entry is assigned a unique accession number, which is called 'Primary (citable) accession number'.<p><a href='/help/accession_numbers' target='_top'>More...</a></p>AccessioniPrimary (citable) accession number: P09871
Secondary accession number(s): D3DUT4
, Q9UCU7, Q9UCU8, Q9UCU9, Q9UCV0, Q9UCV1, Q9UCV2, Q9UCV3, Q9UCV4, Q9UCV5, Q9UM14
<p>This subsection of the 'Entry information' section shows the date of integration of the entry into UniProtKB, the date of the last sequence update and the date of the last annotation modification ('Last modified'). The version number for both the entry and the <a href="http://www.uniprot.org/help/canonical%5Fand%5Fisoforms">canonical sequence</a> are also displayed.<p><a href='/help/entry_history' target='_top'>More...</a></p>Entry historyiIntegrated into UniProtKB/Swiss-Prot: July 1, 1989
Last sequence update: July 1, 1989
Last modified: May 25, 2022
This is version 249 of the entry and version 1 of the sequence. See complete history.
<p>This subsection of the 'Entry information' section indicates whether the entry has been manually annotated and reviewed by UniProtKB curators or not, in other words, if the entry belongs to the Swiss-Prot section of UniProtKB (<strong>reviewed</strong>) or to the computer-annotated TrEMBL section (<strong>unreviewed</strong>).<p><a href='/help/entry_status' target='_top'>More...</a></p>Entry statusiReviewed (UniProtKB/Swiss-Prot)
Annotation programChordata Protein Annotation Program
DisclaimerAny medical or genetic information present in this entry is provided for research, educational and informational purposes only. It is not in any way intended to be used as a substitute for professional medical advice, diagnosis, treatment or care.

<p>This section contains any relevant information that doesn't fit in any other defined sections<p><a href='/help/miscellaneous_section' target='_top'>More...</a></p>Miscellaneousi

Keywords - Technical termi

3D-structure, Direct protein sequencing, Reference proteome

Documents

  1. Peptidase families
    Classification of peptidase families and list of entries
  2. Human chromosome 12
    Human chromosome 12: entries, gene names and cross-references to MIM
  3. Human entries with genetic variants
    List of human entries with genetic variants
  4. Human variants curated from literature reports
    Index of human variants curated from literature reports
  5. MIM cross-references
    Online Mendelian Inheritance in Man (MIM) cross-references in UniProtKB/Swiss-Prot
  6. PDB cross-references
    Index of Protein Data Bank (PDB) cross-references
  7. SIMILARITY comments
    Index of protein domains and families
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